A process for processing polluted carbonaceous substances accumulating as a shredder light fraction, upon the disposal of scrap vehicles, into granulates and pneumatically feeding them into the high-temperature zone of a metallurgical shaft furnace is discussed in German Patent document No. DE-A-44 02 025. A shredder light fraction is formed from disposal, i.e., shredding, of scrap vehicles and other scrap devices, e.g. motorcycles, cars, railway wagons, etc. The light fraction, which accumulates during shredding and which includes mainly organic matter, is ground and prepared to free it from metal particles and enable further processing.
The shredder light fraction is formed by various materials utilized in the scrap vehicle or scrap device, e.g., woven fabrics, various types of plastics, imitation leather, foamed plastics, plastic or cellulose sheathing materials, e.g., consoles, instrument panels, door and roof linings, seals, etc. Accordingly, the structure of the shredder light fraction is fibrous to granular, the fibrous structure being formed from the textile fibers of woven fabrics and the granular structure being formed, in general, by grinding compact plastic parts.
It is essential that the shredder light fraction be processed in a high-temperature zone, e.g., where temperature ranges up to 800.degree. C. should be passed through quickly, because when low temperature carbonization occurs, dioxin and furan formation results. According to DE-A-44 02 025, shredder light fraction is processed by restructuring it through extrusion. The granulates formed by the extrusion are further reduced and pneumatically fed to the high temperature zone of a metallurgical shaft furnace, e.g., a blast furnace.
The process of feeding pneumatically conveyable pulverized substances into a metallurgical vessel through one or several multi-media nozzles located either beneath or above the bath surface is generally discussed in German Patent document No. DE-C-42 38 020, which proposes centrally feeding ground coke suspended in nitrogen through a multi-media nozzle. Externally to, and concentric with, the coke-nitrogen jet, oxygen is injected into the metallurgical vessel. Externally to, and concentric with, the injected oxygen, air is injected into the metallurgical vessel. Externally to, and concentric with the injected air, a protective medium, e.g., natural gas, can be injected into the metallurgical vessel. Heavy melting loss, due to the multimedia nozzles cannot be avoided because breeze, oxygen and natural gas yield a very high flash temperature. Thus, the refractory lining material enclosing the multimedia nozzle shows premature wear.
Furthermore, the process of feeding contaminated pulverized material into the metallurgical vessel by admixing it to the pulverized coke or through other media ducts of the multi-media nozzle is shown in DE-C-42 38 020.